Honeywell T8524 Deluxe Product Data page 13

Symptom
Temperature settings will
not change. (Example:
Cannot set the heating
higher or the cooling lower.) The setpoint
Heating will not come on.
Cooling will not come on.
System On indicator is lit,
but no heat is being
delivered.
Outdoor temperature
not displayed (select
models)
Outdoor temperature
Display is incorrect (select
models)
Possible Cause
The upper or lower Check the temperature setpoints:
temperature limits were • Heating limits are 45°F to 88°F (7°C to 31°C)
reached. • Cooling limits are 48°F to 99°F (9°C to 37°C).
Check Installer Setup numbers 34 and 35 and reconfigure the setpoint
temperature range stops.
stops were configured.
No power to the • Check that C terminal is connected to the system transformer.
thermostat. • Check for 24 Vac between C and R or RH terminals.
System selection is not Set system selection to Heat.
set to Heat.
No power to the • Check that C terminal is connected to the system transformer.
thermostat. • Check for 24 Vac between C and R or RC and Y terminals.
Thermostat minimum off • Wait up to five minutes for the system to respond.
time is activated. • Enter Installer Setup mode number 33. Reconfigure minimum off
System selection is not Set system selection to Cool.
set to Cool.
Heating equipment is Verify operation of heating equipment in system test.
not operating.
Option not activated. Enter Installer Setup number 24 and set to 1. Thermostat must have
OT terminals and a C7089B1000 installed.
Outdoor sensor is Refer to C7089B1000 installation instructions and check wiring
connected incorrectly. between the thermostat and sensor.
Wrong sensor. Replace sensor with C7089B1000 sensor.
T8524 DELUXE ELECTRONIC THERMOSTAT
— If missing 24 Vac:
— check if the circuit breaker is tripped—reset the circuit
breaker.
— check if the system fuse is blown—replace the fuse.
— check if the system switch at the equipment is in the Off
position—set to On position.
— check wiring between thermostat and HVAC equipment—
replace any broken wires and tighten any loose
connections.
— If 24 Vac is present, proceed with troubleshooting.
— If missing 24 Vac:
— check if the circuit breaker is tripped—reset the circuit
breaker.
— check if the system fuse is blown—replace the fuse.
— check if the system switch at the equipment is in the Off
position—set to the On position.
— check wiring between thermostat and HVAC equipment—
replace any broken wires and tighten any loose connections.
— If 24 Vac is present, proceed with troubleshooting.
time (if required).
13
Action
68-0202